Abrasive wheel and mount therefor



2 Sheets-Sheet 1 H. S. INDGE Filed June'25, 1935 mm 9n ABRASIVE WHEELAND MOUNT THEREFOR H/ M K J I March 1, 1938.

INVENTOR HERBERT 51MB GE A T ToRNEY WITNESS mzzh Margh l, v1938. I s,[NDGE 2,110,086

I ABRASIVE WHEEL AND MOUNT THEREFOR Filed June' 25, 1935 2 Sheets-Sheet:2

I INVENTOR Wrnwss5 HERBERT 5. I GE ,JM M 542M ATTORNEY Patented Mar. 1,1938 Q PATENT OFFICE ABRASIVE'WHEEL AND MOUNT THEREFOR.

- nerberts. Indge, Westboro, Mass, assignor to Norton Company,Worcester, Mass., a corpora ton of Massachusetts Application June 25,

2 Claims.

This invention relates to abradant wheels and apparatus for mountingthem.

One object of the invention is to'provide an abradant wheel ofrelatively large peripheral surface area. Another object of theinvention is to provide a conical abradant wheel of relatively greatlength with relation to its average diameter. Another, object of theinvention is to provide a wheel mounting and wheel construction offrusto-conical formwhich shall reduce wheel wastage. Another object ofthe invention is to provide a wheel construction of interchangeablesections. Other objects will be in part obvious or in part pointed outhereinafter.

The invention accordingly consists in the features of construction,combinations of elements and arrangements of parts, as will beexemplified in the structure to be hereinafter described, and the scopeof the application of which will be indicated in the following claims.

, In the accompanying drawings; in which is disclosed one of manypossible embodiments of the mechanical features of the invention,

Figure 1 is a view of a portion of a continuous lapping machineillustrating a pair of abradant wheels and mounting apparatus thereforapplied thereto, one wheel being shown in axial section and the other infront elevation;

Figure 2 is a vertical sectional view taken on the line 2-2 of Figure 1;

Figure 3 is a vertical sectional view taken on the line 3-3 of Figure 1.V

This invention is in part disclosed in my copending application SerialNo. 5,271, filed February 6, 1935, now Patent No. 2,087,874, dated July20, 1937, relating to lapping machines. In that application I havedisclosed a lapping machine having a pair of frusto-conical lappingwheels adapted to finish a cylindrical work-piece which i is maintainedbetween the wheels by guides, the work-piece being fed through themachine by skewing one or both of the wheels. The aforet said copendingapplication further discloses an apparatus for shaping the originallyfrusto-conical wheels so that, despite the fact that they are skewed,they will effectively lap a true cylindrical work-piece. Such shapingmodifies the peripheralsurface of each wheel by producing therein aslight concavity. The dressing apparatus disclosed in thecopendingapplication will not be described in detail herein particularlyinsomuch as, so far as the present invention is concerned,

, any substitute might be employed; nevertheless,

for a clearerunderstanding of the shapes of the wheels according to thepresent invention, it is 1935, Serial No. 28,236 (01. 51-103) noted thatthe dressing device is mounted for traverse between the wheels in arectilinear path, and, insomuch, as herein described, the wheels aremounted for angular adjustment on an axis at right angles to their axisof rotation, dressing or truing of the wheels with such dressing devicemay produce a concave contour therein if they are skewed with respect tosuch rectilinear path. Insomuch as I rely for the production of certainefiects in lapping upon moving abrasive material at an angle to the axisof the work-piece, which is not a right angle, I skew the axes of thewheel spindles with respect to the saidrectilinear path and dress thewheels to produce such concave surface which generates a truecylindrical surface or leaves a true cylindrical surface on theworkpiece. So faras certain claims are concerned, therefore, each wheeland each wheel section herein described may be considered to have aslight concavity in its peripheral surface; insomuch as ordinarily suchconcavity is of a slight degree, it has not been illustrated in thedrawings, and insomuch as, further, the degree of concavity is avariable depending upon setting of the wheels and the particular type orwork-piece being lapped. The present application is directed to theconstruction and mounting of the wheels per se. In the manufacture ofabrasive wheels there are and have been certain practical limits on thesize thereof both in an absolute sense and relatively with respect tothe ratio of thickness to diameter. Whatever might be regarded as thelimit in either of these respects, it is notthat a larger wheel or athicker wheel could not be made, but that it is not convenient andeconomical to do so. In the case of large wheels and wheels which areextremely thick with respect to their diameters, a disproportionatenumber might have to be rejected because of the development of cracks inthe firing or baking or other heat treatment or otherwise; such wheels,however made, are difiicult to handle while in process of. manufacture,a so-called green wheel (an This plate II has a milled or planedhorizontal upper surface 1-! 2jupon which rests a table l3. A

trunnion'l4 having a vertical axis extends downwardly from the underside of the table I3 and fits in a, bore IS in the supporting plate II,and

thus the table I3 is restrained against any hori- The table I3 supportsanabrasive wheel and spindle to be described, and a similar wheel ismounted above it. Considering now the support for the upper wheel, themachine of the copending application referred to has a column attachedto thebase H), which column is not shown herein as, so far as thefeatures of this invention are concerned, it may be of any desired form,and mounted on the column is a slide adjustable in a vertical direction,on the column, the slide beinglikewise not shown herein, and extendingforwardly from the slide is an overhanging support 20 which may beintegral with the slide; thus in a sense the casting 20 shown in thedrawings is part of said slide. On the under side of the overhangingsupport or over-arm 20 is a large flat plane surface 2| extendingapproximately over the horizontal upper surface l2 of the supportingplate ll. Held against this surface 2| is a table 22, and a trunnion 23fitting in a bore 24. mounts the table 22 for angular adjustment. Thetable 22 is prevented from falling and is held against the surface 2| bymeans of cooperating segmental guiding surfaces 25 and 26. The trunnion23 may be provided with radial supporting plates 21 to assist insupporting the load. The upper and lower abrading wheels 30 and 30arespectively are, atvleast initially in this embodiment of theinvention, frusto cones, and they and the journaling means for them andtheir mounting upon their spindles being similar, I have Shown only theupper wheel 30 in cross-section and it should be understood that thejournaling means and spindle supports for the lower wheel 30a is similar to, that for the upper wheel 30. It will also be noted frominspection of the drawings that the frusto-conical wheels 30 and 30a.are oppositely disposed and the locus of the abrading throat is betweenthe wheels, the work guides not being shown herein.

Still referring to Figure 1, extending downwardly from the table 22 anddesirably integral with his a head 3|. Likewise a head 3la extendsupwardly from the table l3. Each head is hollow as shown in the case ofthe head 3|, and formed on the inside thereof is a roller bear-, ingrace recess 32. The "outer race 33 of a roller bearing seats in therecess 32 while the inner race 34 seats on-a cylindrical portion 35pro-.

vided on a spindle 3G. Conical rollers 3'll are shown located betweenthe races 33 and 34.

, The inner race 34 is held on the spindle 36 by means of a shoulder 38.on the spindle at one side of the race 34, and a sleeve 39 on the othersidethereof. The thrust on the sleeve 39 is taken by an inner race 40 ofa. second roller bearing which is mounted on a cylindrical portion 4| ofthe spindle 36 and which also abuts a square shoulder 42 on the spindle.Conical rollers 43 are located between the inner race 40 and an outerrace 44 which is seated in a recess 45 provided in an annular member 46which is secured in the head 3| fitting in'a cylindrical bore 41thereof. The annular member 46 has a circular recess 48 for thereception of a cap 49 which keeps grit out of the bearings and oil orgrease therein if desired. In order to take the thrust on the inner race40 and to position bothraces 40 and 34 upon the spindle 36, the spindle36 is threaded at 50 and a couple of nuts 5| and 52 are placed on theportion 50, the inner nut 52 beingin contact with the race 40. Thuswhenthe nuts. are tightened thrust is exerted from theinner nut 52'to therace 40, from there to the sleeve 39 to the inner race 34 and againstthe shoulder 39. Insornuch as the outer races 33 and 44' are heldbetween the recesses 32 and 45, the bearing means described constitutesan anti-frict'ion radial and, thrust bearing for the left-hand end ofthe spindle 36, there being a similar bearing in the head 3la for thesimilar spindle 36a.

The spindle 36 may be driven from inside the head 3|. Keyed to thesleeve 39 is a worm wheel 55 which is driven by a Worm 56 on a shaft 51whose axis is at right angles to that of the spindle 36. The worm wheel55 extends through a cutout 58 in a sleeve 59, and for the remainingfeatures of the driving mechanism I will now refer to the similarconstruction in connection with the head 3 la, as illustrated in thecross-sectional view of Figure 3. The spindle 36a has keyed thereto asleeve 39a to which is keyed a worm wheel 55a' which is driven by a worm56a keyed to a shaft 51a. There is a. cutout 58a in a sleeve 59a whichhas a flange portion 60a that is bolted to the head 3la by bolts 610.,there being a shoulder 62a which fits in a bore 63a in the head 3la.Thus the sleeve 59a is held in a fixed position in the head 3Ia, and theother end of the sleeve 59a fits in a bore 64a in the other side of thehead Ma.

The worm 56a abuts a shoulder 65a on the shaft 51a, this shoulderreceiving the driving thrust. The other end of the worm 56a abuts asleeve 66a on the shaft 51a. The shaft 51a has a reduced portion 61awhich is threaded at the end. A lock nut 68a holds an inner race 69a ofa ballbearing on the reduced portion 61a, but a slight clearance isprovided, as shown. The thrust on the shaft 51a is taken by the bearingsof a driving motor Illa but when the motor is slowing down, or when thethrust on the worm 56a is reversed for any reason, the slight left-handthrust of the worm 56a. is taken by thesleeve 66a, transmitted to theinner race 69a, and taken by bearing balls Ila and thus transmitted toan outer race 12a. and thence to a bearing cap 13a. The outer race 12ais positioned in a recess-14a in the sleeve 59a and held therein by ashoulder 15a or the bearing cap 13a. The bearing cap may be held inposition by bolts 16a. Thus the ball bearing consisting of races 69a,12d and balls Ila is essentially a radial bearing,

The other end of the shaft 510. passes through a stufling box 30a thatis bolted by bolts 8la to the sleeve 59a, the stufiing box having a headmotor 10a through a coupling 90a. The motor 10a is'moun'tedon a platform9Ia which is integral with an extension 92a of the table I3. Thus thedrive is not interfered with by adjustments in angular position of thewheel 30a.

Considering again the upper spindle 36, the

"mechanism for driving it is similar to that al- 'shown'in the copendingapplication referred to.

ready described, although .a different means of allowing for adjustmentsin the angular position of the wheel 30 may be provided, for example asIn order to seal oil or grease in the roller bearings described and tokeep grit therefrom, packing I 95 and a gland 96 may be provided. Thegland 96 consists of nearly over-lapping annular portions on the outsideof the head 3| and on a flange portion 91 of a hollow spindle or sleeve99 which is connected to the driving and supporting spin-- dle 36 by aspline connection I00.

Still considering the upper part of Figure 1, upon the hollow spindle99I mount a plurality of abrasive wheels IOI, I02, I03, I04, I05, I06, I01and I08. Each of these is a frusto-cone with an axial bore just fittingthe outside of the hollow spindle 99. The small end of the wheel IOI hasa diameter-just equal to that of the large end of the wheel I02, and allthe others down to the end wheel I08 have diameters equal to that of thelarge ends of the adjacent wheels respec- I tively. Preferably eachwheel is of the same thickness as allthe others. While this inventioncontemplates the use of any kind of wheel so far as composition isconcerned, I have achieved excellent results in a. lapping machine usingfine grain silicon carbide ina shellac bond. Other grain may be used, asalumina, emery, corundum, garnet, quartz, and other bonds, as ceramic,rubber, synthetic resins, sodium silicate.

In the assembly of the entire wheel 30, the component wheels I to I08are slipped onto the spindle 99 in the order described and shown, andwith the wheel IOI against the flange 9'I. Desirably the sides of eachwheel excepting the large Gil side of the wheel IM and the small side ofthe wheel I 08 are coated with a suitable cement, such as, in the caseof shellac bonded wheels, a coating of shellac. A washer I09 and a nutIIO fltting on a threaded portion III of the spindle 99 secure theindividual wheels together as a unit and compress the cement so that itwill set. Before explaining the features of the wheel 30 further, Ishall complete the description of the mounting means.

Still referring to the upper part of Figure 1, the spindle 36 adjacentthe right hand end of the outer hollow spindle 99 has a threaded portionII2 on which is located a nut II3 which clamps the spindle 99 against ashoulder I on the spindle 36 adjacent the flange 91. At the right-handend of the spindle 36 is a reduced cylindrical portion I-I5. Referringnow to the upper righthand part and also to the lower left-hand part ofFigure 1, and also to Figure 2, the table I3 has attached to it waysII6a and the table 22 portion I I of which is supported and j'ournaledin the head I".

Considering now the journals for the outer ends of the inner spindles,and referring to the upper right-hand part of Figure 1 and also toFigure 2, a cylindrical recess I 20 is formed in the head I", whichrecess is open at the righthand end and has a shoulder I2I and anannular flange I22 at the left-hand end. An outer casing member I23'flts in the recess I20 against the shoulder I2I and thismember I23 hason either side thereof annular plates I24. An outer race I25 fitsbetween these three last mentioned parts between which outer race I25and an inner race I26 are-located cylindrical rolls I21. The inner raceI26 is press-fitted upon a sleeve I20 which removably flts the reducedportion 5. There is a clearance between the annular plates I24 and thesleeve I28 while a nut I29 maintains the assembly of the anti-frictionbearing when it is slid off the reduced portion H5. A hearing cap I30fitting in the recess I20 together with the annular flange I22 seals thebearing for retention of oil or grease and the exclusion of grit,while'it is noted that'the flange I 22 is just clear of the sleeve I28.

By reason of the construction described, the head .I-II may be slid offtheend of the spindle 36 at any time. The bearing just described is aradial bearing and takes no thrust, and preferably the heads I I1 and IIIa are not clamped upon the ways H6, H8 and 611, Had, thus permittingthe parts to find their natural position with- The bearings includingthe rollers B'I and 43 are built to withstand the strain of the weightof spindles and wheels without any outer support, as these hearings aredouble radial and thrust bearings spaced a substantial distance apart.Consequently it is a simple matter to place the wheels IOI to I08 orIOIa to I08a upon the spindle 99 or 99a and secure them in place withthe washer I09 and nut H0 or washer I09a and nut Ba. 7

The wheels having been assembled, the machine may be used as describedin the copending application referred to. As the machine is used, the.wheels-will be dressed and trued from time to time to take care of wheelwear and ad justments. Each different position of skew of the wheels onthe axes I 4 and 23 respectively requires a new truing of the wheels in,order to achieve the best results in lapping. Consequently from theabove causes and also by reason of normal wheel wear, the respectivewheels 30 and 300. are continually becoming smaller in diameter. Whenthe work-pieces are about to contact the washers I09 and "39a, I removethe wheels 30 and 30a (or only one of them if only one is considerablyreducedjn diameter) and the sections may be readily separated byknocking them with a lead hammer, as the cement is not and should not bea permanent adhesive. However, I prefer merely to knock off the smallsection I08 or I 03a, and then I slide a new-unused section IOI or IOIaupon the spindle 99 or 99a coating the small face thereof with a cement.and then slide the 76 tighten up the nut H0 or lllla as before. Theresult is a, fresh wheel, which may be trued to exact frusto-conical orother spiral form or shape, and the total discarded or unused wheelvolume is indicated by the very close cross-hatching on section IN onFigure 1. How this compares with what would be discarded, were unitwheels used can beappreciated by reference to Figure 1, drawing linesfrom the outside of flange 91 to the outside of washer lll9.-Furthermore, by means of the construction described, the renewal ofwheels may be made very quickly. Preferably wheels are renewed when allsections have been worn so that their large diameters are equal to theoriginal size of their small diameters, as by this procedure a minimumof dressing or truing is required. A circle may'be painted on eachwheel, on the small side thereof, to represent this diameter forthesmall wheel I08 or I080,

since eventually every wheel moves to that posi-' tion. It will be notedthat all nuts have been shown as spanner nuts which facilitates theassembly and disassembly of the parts.

Although I have described the assembly of the wheels 30 and 30a upon thespindles 99 and 99a with the latter upon the spindles 36 and 360., it isquite convenient to remove the latter spindles from the former spindlesfor this purpose.

old sectio'ns llll to I01 inclusive, or lid to lMa. inclusive upon thespindle 99 or 980. I then 1 posite wheel in which the variousobjectshere- It will thus be seenthat there has been pro-- vided by thisinvention an apparatus and a cominabove set forth together with manythoroughly practical advantages are successfully achieved.

As many possible embodiments may be made of the above invention, and asmany changes might bemade in the embodiment above set forth, it is as beunderstood that all matter hereinbefore set forth, or shown in theaccompanying drawings,

'is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In apparatus of the class described, a pair of tables in parallelrelationship, a pair 6f fixed headsone on each table, a pair of movableheads one on each table, spindles journaled in said heads, each spindleextending between a fixed head and a movable head and each movable headbeing movable in the direction of the spindle axis, and the fixed headon one table being opposite the movable head on the other table, andfrustoconical abrasive wheels mounted on said spindles with the largeend of one wheel opposite the small wheel of the other.

2. In apparatus as claimed in claim 1, the combination with the partstherein specified of a plurality' of frusto-conical abrasive sectionsconstituting the frusto-conical abrasive wheels.

HERBERT s. INDGE.

